Which system of equations is represented by the graph?

[Karthik]

Which system of equations is represented by the graph? (2 points)

a. y = x2 - 6x - 7
x - y = 1

b. y = x2 - 6x + 7
x + y = -1

c. y = x2 + 6x - 7
x - y = 1

d. y = x2 + 6x + 7
x + y = 1